The present invention relates to deodorizing compositions. More particularly, the invention relates to antimicrobial deodorizing compositions for this purpose.
Body odor is formed when fresh perspiration, which is odorless per se, is decomposed by microorganisms. This process takes place principally, though not solely, in the axilla, and a number of microorganisms are involved, each having different activity and leading to body odor of different strength and unpleasantness. The most prominent odor-producing microorganisms include aerobic diphtheroids, primarily Corynebacterium species and coagulase negative cocci such as Micrococcaceae.
Various microorganisms are found in different proportions in different individuals, and this is a reason for the fact that different individuals exhibit different body odors.
The commercial cosmetic deodorants are based on different active principles. The formation of perspiration is suppressed according to the known art by astringents, predominantly aluminum salts such as aluminum hydroxychloride. Apart from the denaturation of the skin proteins, however, the substances used for this purpose clog the pores, interfere drastically with the heat regulation of the axillary region, may cause cancer and other diseases, and should at best be used in exceptional cases. According to another accepted prior art method, the bacterial flora on the skin is reduced by antimicrobial substances. Finally, body odor can also be concealed by fragrances, which, however, is the least able to meet the aesthetic needs of the consumer, as the mixture of body odor and perfume fragrance smells rather unpleasant.
According to a recent patent on this subject (U.S. Pat. No. 5,318,778), deodorants should fulfill the following conditions:
1) The biological processes of the skin must not be impaired.
2) The deodorants should have no distinct intrinsic odor.
3) They must be harmless in the case of overdosage or other unintended use.
4) They should not concentrate on the skin after repeated use.
5) It should be possible to incorporate them easily into commercial cosmetic formulations.
Those which are known and usable are both liquid deodorants, for example aerosol sprays, roll-ons and the like and solid preparations, for example deodorant sticks, powders, powder sprays, intimate cleansers etc.
U.S. Pat. No. 5,318,778 approaches the problem by employing antibiotics, which are said to be specific microbiocides which predominantly destroy odor-forming microorganisms.
All the prior art methods suffer from severe drawbacks: they require the masking of body odor which has already formed prior to the application of the deodorant, because the destruction of axillary microorganisms does not remove already formed odor. They require the use of antimicrobial agents which must have a long-lasting activity on the skin, because the skin flora is not completely exterminated by their application, and, quite importantly, they very often leave unpleasant stains or halos on the cloths, particularly at and around the axilla. Also the safety of many antiperspirants is dubious, due to the presence of potentially harmful components, and the result is often unpleasant, because of the unnatural odor obtained.
Notwithstanding the many efforts made during many years, and the magnitude of the problem involved, the art has failed to provide deodorizing compositions which are convenient and safe to use, which are effective for a long time. The inventors have now surprisingly found, and this is an object of the invention, that the aforesaid goals can be achieved by using a well known harmless and effective natural agent: Henna.
Henna (Lawsonia inermis) is a small shrub growing in Arabia, North Africa, Iran and the East Indies. Dried leaves are a source of green powder used in cosmetics. Although henna paste has been used as a remedy for boils, wounds and some mycotic infections, there are few data on the activity of extracts.
S. S. Bhatnagar et al. [Biological activity of indian medicinal plants. Ind. J. Med. Res. 49: 799-813, 1961] examined antibacterial, antitubercular and antifungal action of 351 Indian plants. The extraction method was first using petrol (b.p. 40-60xc2x0 C.), followed by extraction of the extracted powder with either 90% or 10% methanol. They found that henna powder was active against all three categories, although they did not list the kind of extracts which were active. One of the few scientific papers discussing extraction of henna for antibacterial activity is that of F. Malekzadeh [Antimicrobial activity of Lawsonia inermis L., Applied Microbiology, 16:663-664, 1968]. He studied aqueous extracts and found that while both Gram + and Gram xe2x88x92 bacteria were inhibited, inhibitory action was greatest against Bacillus anthracis and least against Staphylococcus aureus. 
One known component of henna is lawsone, a napthoquinone pigment which has antibacterial activity against oral species. [N. Didry, L. Dubreuil and M. Pinkas, Activity of anthraquinonic and naphthoquinonic compounds on oral bacteria, Pharmazie, 49:681-683, 1994].
While henna has been used since biblical times as a colorant, and has been mentioned anecdotally as an antiperspirant and antibacterial agent and as a source of gallic acid which inhibits xe2x80x9cStreptococcus aureusxe2x80x9d slightly [Handbook of Medicinal Herbs, p. 274], the direct use of henna extract has been always limited due to its high staining power, which is undesirable both to skin and clothing.
Z. F. Mahmoud et al. [Constituents of Henna Leaves Growing in Egypt, Fitoterapia, 51:153-155, 1980] isolated seven crystalline compounds from Egyptian henna leaves. They write that henna has been used for preserving mummies, and has been used for skin diseases and tinea of the legs. They extracted powdered leaves at room temperature with ethanol. The ethanolic extract was concentrated under vacuum and partitioned between chloroform and water. The aqueous layer was successively extracted with ethyl acetate, etc. They cite that the lawsone, the dyeing principle of henna has bacteriostatic properties, citing the work of Karawya et al. [M. S. Karawya, A. S. M. Wahha and A. Y. Zaki, A study of the lawsone content in henna, Lloydia, 32:76, 1969].
Karawya et al. did not actually check antibacterial activity, but rather established a simple method for estimating the quantity of lawsone. They also mention antifungal and antibacterial properties, citing the work of Hoffman et al. [O. Hoffmann, W. Ostenhof and O. Krapupp. Bacteriostatic quinones and other antibiotics. Montsh. Chem. 77:86-96, 1947].
Black Henna, according to the information given by Alban Muller International, is a mixture of henna powder, and black powder from the plant Indigofera tinctoria. According to Anand et al. [K. K. Anand, D. Chand and B. J. Rah Ghatak, Protective effect of alcoholic extract of Indigofera tinctoria Linn. in experimental liver injury, Indian Journal of Experimental Biology,19:685-687, 1979], I. tinctoria is an annual herbaceous shrub 4-6 feet high found throughout India. It was cultivated in India, China and other countries of the east as a source of Indigo (a colorant that dates back to biblical times, according to B. Chisik in his book in Hebrew, xe2x80x9cTreasure of plantsxe2x80x9d (Otzar Ha""Tsmachim), Vol. 1, p. 333, Hertzlia, Hotzahat Hamechaber, Tsixe2x80x3b). The extract of the plant is used in epilepsy, nervous disorders and bronchitis. The authors extracted the aerial part of the plant (powdered) with 50% alcohol. They then checked and found marked antihepatotoxic effect in animals.
In another paper (K. K. Anand, D. Chand, B. J. Rah Ghatak, and R. K. Arya, histological evidence of protection by Indigofera tinctoria Linn. against carbontetrachloride induced hepatotoxicityxe2x80x94an experimental study, Indian Journal of Experimental Biology, 19: 298-300, 1981), the authors presented histological evidence for protection of liver cells, against carbontetrachloride induced hepatotoxicity using a 50% ethanolic extract.
In another article by R. Han (Highlight on the studies of anticancer drugs derived from plants in China, Stem Cells 12:53-63, 1994), the author reports that indirubin from Indigofera tinctoria is useful for the treatment of chronic myelocytic leukemia.
The fact that henna extracts have never been considered for use in respect of body odor control is probably related, inter alia, to the fact that henna extract retain a high staining power and thus any composition containing such extract is inherently deleterious to clothing and is not to be considered for application to the skin in the vicinity of clothing.
It is an object of the present invention to provide body-odor controlling compositions containing henna extracts, which are efficient to control skin microorganisms which are responsible for body odor.
It is another object of the invention to provide such deodorizing composition based on henna extracts, which can be used to control body odor, without incurring the risk of staining clothing.
It is yet another object of the invention to provide deodorizing compositions which are selective toward specific skin microorganisms, and that therefore permit to control body odor without harming the natural flora of the skin.
It is still another object of the invention to provide a method for deodorizing human or animal skin, and for preventing the formation of body odor.
It is a further object of the invention to provide a process for manufacturing a deodorizing composition of the invention.
Other objects and advantages of the invention will become apparent as the description proceeds.
In one aspect, the invention is directed to a deodorizing composition comprising as an antimicrobial agent an effective amount of an extract of Lawsonia inermis, or of an antimicrobially active fraction thereof.
According to one preferred embodiment of the invention the deodorizing composition further comprises materials extracted from Indigofera tinctoria. 
It is possible, to include in the deodorizing composition according to the invention additional conventional deodorant components, such as antibacterial and antiodor materials, e.g., essences, such as essential oils, triclosan, triethyl citrate.
The deodorizing composition of the invention is particularly suitable for use as a pre-shower deodorant. Thus, it is possible to apply the composition of the invention and then to remove it using regular detergents. Thus, the objects of the invention are achieved but not undesirable staining of clothing takes place.
In another aspect the invention is directed to a process for manufacturing a deodorizing composition, which process comprises extracting natural material comprising Lawsonia inermis with a suitable extraction solvent, and using the extract so obtained as such, or in a suitable carrier. Such suitable carriers may be chosen, but are not limited to a group of aqua, alcohol and oil based carriers such as water, ethanol and isopropylmyristate, respectively.
In a further aspect, the invention is directed to a process for manufacturing a deodorizing composition, said process comprising extraction of natural material comprising Indigofera tinctoria with a suitable extraction solvent, and using the extract so obtained as such, or in a suitable carrier.
According to a preferred embodiment of the invention, when the natural material employed as raw material in the process is derived from Lawsonia inermis, said natural material may further comprise natural material derived from Indigofera tinctoria. Suitable raw materials for the process of the invention are red henna and black henna.
While the invention is not limited to the use of any particular raw material, or any particular form of raw material, according to a preferred embodiment of the invention the raw material employed for the extraction process is a henna powder.
The invention, inter alia, is directed also to a method for deodorizing and/or preventing the formation of body odors, comprising applying to the axilla and/or other body part affected by body odor a deodorizing composition comprising as an antimicrobial agent an effective amount of an extract of Lawsonia inermis, or of an antimicrobially active fraction thereof, for a period of time sufficient to inhibit the growth of skin microorganisms responsible for body odor formation, and then washing off the deodorizing composition using conventional detergents.
Similarly, the invention is also directed to a method for deodorizing and/or preventing the formation of body odors, comprising applying to the axilla and/or other body parts affected by body odor a deodorizing composition comprising as an antimicrobial agent and effective amount of an extract of Indigofera tinctoria, or of an antimicrobially active fraction thereof, for a period of time sufficient to inhibit the growth of skin microorganisms responsible for body odor formation, and then washing off the deodorizing composition using conventional detergents.
In another aspect, the invention is directed to an antimicrobial composition comprising an extract of Indigofera tinctoria or Indigofera tinctoria-containing material. The invention also specifically makes provision for an antimicrobial composition effective against Staphylococcus aureus, said composition comprising an extract of of Indigofera tinctoria or Indigofera tinctoria-containing material. The aforementioned extract may be produced using one of several different extracting solutions, including aqueous, and alcohol in water. In the latter case, according to a preferred embodiment, the concentration of alcohol in the water is in the range of 10 to 30 %. While several different alcohols may be used, a preferred alcohol is ethanol.
In a further aspect, the invention is directed to the use of Indigofera tinctoria extracts as an antimicrobial agent effective against Staphylococcus aureus. It has been surprisingly found, as will be apparent to the skilled person, from the detailed description to follow, that extracts of Indigofera tinctoria and of black henna, which contain Indigofera tinctoria, are very effective in the inhibition of Staphylococcus aureus growth, while red henna, which does not contain Indigofera tinctoria, is only partially effective (see, e.g., Table VII).
In another aspect, the invention is directed to an antimicrobial composition comprising an extract of Lawsonia inermis-containing material. The invention also specifically makes provision for an antimicrobial composition effective against Corynebacterium species, said composition comprising an extract of Lawsonia inermis-containing material. The aforementioned extract may be produced using one of several different extracting solutions, including aqueous, and alcohol in water. In the latter case, according to a preferred embodiment, the concentration of alcohol in the water is in the range of 10 to 30%. While several different alcohols may be used, a preferred alcohol is ethanol.
The invention further provides for the use of a Lawsonia inermis extract as an antimicrobial agent for the inhibition of Corynebacterium species.
The above and other characteristics and advantages of the invention will be more readily apparent through the following examples of preferred embodiments thereof
The Extraction Process: One ml of solvent was added to 0.1-0.2 gr of henna powder. The mixture was vortexed for 10 min and the samples were centrifuged for 30 min at 10000 rpm. The supernatant was collected and referred to as the extract. The extract was then filtered through a 0.22 or a 0.45 xcexcm filter.
Following centrifugation, the extract was allowed to stand at room temperature. It was noted that despite the previous centrifugation and filtration, a fine dark precipitate slowly collected towards the bottom of the aliquots. The amount of precipitate decreased as the percentage of alcohol increased. When this was observed, it was decided to check whether this precipitation resulted in a difference in antibacterial activity. The extract was centrifuged for an additional 30 min at 10000 rpm, and the upper layer (relatively free from precipitate) and the lower layer (rich in precipitate) were separated and tested separately for antibacterial activity. Almost no difference was found between the diameter of the inhibition zones, although the lower phase (rich in precipitate) formed a more transparent inhibition zone.
Inhibition Test: The antimicrobial activity of the various extracts was examined by applying samples (5 xcexcl) onto lawns of axillary bacteria. Following incubation of 24 hours at 37xc2x0 C., inhibition was determined by measuring the diameter of the growth inhibition zone (in cm). In the tables, xe2x80x9c+xe2x80x9d indicates full growth inhibition(transparent zone), xe2x80x9cxe2x88x92xe2x80x9d indicates lack of inhibition, and xe2x80x9c+/xe2x88x92xe2x80x9d indicates partial inhibition (translucent zone).
For the purposes of comparative testing, 5 xcexcl aliquots of either red or black henna extracts (20% w/v in 20% v/v ethanol) are applied to the bacterial lawns.
Red henna extract is considered active when:
1. (a) it inhibits the growth of C. xerosis, 
(b) the inhibition zone is transparent or translucent, and
(c) the diameter of the inhibition zone is greater then 0.5 cm, and
2. it does not inhibit the growth of S. epidermidis (although in some cases, a translucent xe2x80x9cinhibitionxe2x80x9d zone is seen).
Black henna extract is considered active when:
1. (a) it inhibits the growth of C. xerosis, 
(b) the inhibition zone is transparent or translucent, and
(c) the diameter of the inhibition zone is greater then 0.5 cm, and
2. (a) it inhibits the growth of S. epidermidis, 
(b) the inhibition is transparent, and
(c) the diameter is bigger then 0.5 cm.
Some purified components of henna (according to the specification sheet given by Alban Muller International) were tested, and no activity similar to that described herein was found. Solutions of lawsone, 1,4-naphthoquinone and gallic acid were tested for growth inhibition of Staphylococcus eidermidis and Corynebacterium xerosis. 
The results are detailed in Table I below:
Although 1,4-naphthoquinone which is supposed to be found in henna leaves inhibits the growth of the two strains, it seems that the activity which the inventors have found is not due to this component as the extract of red henna of the invention inhibits only C. xerosis. 